[JENA-679] Use an alternative implementation of a FRuleEngineI

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Jena 2.11.1
• Fix Version/s: Jena 2.11.2
• Component/s: Reasoners
• Labels: patch
• Assignee: Dave Reynolds
• Reporter: Sébastien Boulet
• Created: 16/Apr/14 16:17
• Updated: 18/Apr/14 14:56
• Resolved: 18/Apr/14 14:15

Description

Give the possibility to use an alternative FRuleEngineI implementation.
My proposition is to introduce a singleton factory FRuleEngineIFactory.

com.hp.hpl.jena.reasoner.rulesys.impl.FRuleEngineIFactory.java

public class FRuleEngineIFactory {
    private static FRuleEngineIFactory instance = new FRuleEngineIFactory();
    public static void setInstance(FRuleEngineIFactory instance) { FRuleEngineIFactory.instance = instance; }
    public FRuleEngineIFactory getInstance() { return instance; }
    
    public FRuleEngineI createFRuleEngineI(ForwardRuleInfGraphI parent, List<Rule> rules, boolean useRETE) {
        FRuleEngineI engine;
        if (rules != null) {
            if (useRETE) {
                engine = new RETEEngine(parent, rules);
            } else {
                engine = new FRuleEngine(parent, rules);
            }
        } else {
            if (useRETE) {
                engine = new RETEEngine(parent);
            } else {
                engine = new FRuleEngine(parent);
            }
        }
        return engine;
    }
}

This factory will be used by existing classes.

com.hp.hpl.jena.reasoner.rulesys.BasicForwardRuleInfGraph

    
@Override
protected void instantiateRuleEngine(List<Rule> rules) {
    engine = FRuleEngineIFactory.getInstance().createFRuleEngineI(this, rules, false);
}

com.hp.hpl.jena.reasoner.rulesys.FBRuleInfGraph

@Override
protected void instantiateRuleEngine(List<Rule> rules) {
    engine = FRuleEngineIFactory.getInstance().createFRuleEngineI(this, rules, useRETE);
}

com.hp.hpl.jena.reasoner.rulesys.RETERuleInfGraph

    
@Override
protected void instantiateRuleEngine(List<Rule> rules) {
    engine = FRuleEngineIFactory.getInstance().createFRuleEngineI(this, rules, true);
}

And i could replace the factory instance by my own instance :

FRuleEngineIFactory.setInstance(new CustomFRuleEngineIFactory());

I will propose a patch soon.